Sensing Air Conditioner Parameters

ABSTRACT

A system includes a cloud-based system and a plurality of systems for sensing air conditioner parameters coupled to the cloud-based system. Each of the plurality of systems for sensing air conditioner parameters senses parameters about a respective air conditioning system and forwards the sensed parameters to the cloud-based system. The cloud-based system receives the parameters from the plurality of systems for sensing air conditioner parameters, determines a maintenance condition, and forwards the maintenance condition to an interested party.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application No. 62/789,306, entitled “Sensing Air Conditioner Parameters,” filed on Jan. 7, 2019, which is incorporated by reference in its entirety.

BACKGROUND

In many parts of the world air conditioning is an important factor in the quality of everyday life. Air conditioner systems are often complex and beyond the skills of most laymen to maintain. Such systems often include a compressor/condenser, which can be dangerous for an unskilled person to attempt to maintain. Further, it may be difficult for the average person to know when maintenance of such a system is advisable or necessary.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a block diagram of a system for sensing air conditioner parameters.

FIG. 1B is a simplified block diagram of an air conditioning system.

FIG. 2 is a rendering of components for sensing air conditioner parameters.

FIG. 3 is a rendering of a sensor for detecting a temperature of a heat-conductive line.

FIG. 4 is a rendering of the connection of sensors to an air conditioner compressor/condenser.

FIG. 5 is a rendering of components for sensing air conditioner parameters.

FIG. 6 is a rendering of a generator positioned over a compressor/condenser fan.

FIG. 7 is a rendering of a generator positioned over a compressor/condenser fan.

FIG. 8 is a rendering of a generator positioned over a compressor/condenser fan.

FIG. 9 is a rendering of a device for sensing air conditioner parameters coupled to the air conditioner compressor.

FIG. 10 is a rendering of components, some do-it-yourself install and some requiring a tech installation, for sensing air conditioner parameters.

FIG. 11 is a rendering of components for sensing air conditioner parameters.

FIG. 12 is a rendering of components for sensing air conditioner parameters.

FIG. 13 is a rendering of components for sensing air conditioner parameters.

FIG. 14 is a rendering of components for sensing air conditioner parameters.

FIG. 15 is a rendering of components for sensing air conditioner parameters.

FIG. 16 is a rendering of a generator.

FIG. 17 is a rendering of a generator.

FIG. 18 is a rendering of a generator.

FIG. 19 is a rendering of sensors for detecting a temperature of a heat-conductive line.

FIG. 20 is a rendering of sensors for detecting a temperature of a heat-conductive line.

FIG. 21 is a rendering of a generator.

FIG. 22 is a rendering of sensors for detecting a temperature of a heat-conductive line.

FIG. 23 is a rendering of a cable.

FIG. 24 is a rendering of a cable.

FIG. 25 is a rendering of a power draw sensor.

FIG. 26 is a rendering of the connection of sensors to an air conditioner compressor.

FIG. 27 is a rendering of the connection of sensors to an air conditioner compressor.

FIG. 28 is a rendering of an air conditioner compressor/condenser with a generator installed.

FIG. 29 is a rendering of an air conditioner compressor/condenser with a generator installed.

FIG. 30 is a rendering of an air conditioner compressor/condenser with a generator installed.

FIG. 31 is a perspective view of a sensor for detecting a temperature of a heat-conductive line.

FIG. 32 is a plan view of a sensor for detecting a temperature of a heat-conductive line.

FIG. 33 is a perspective view of a sensor for detecting a temperature of a heat-conductive line with a hidden top shell.

FIG. 34 is a plan view of a sensor for detecting a temperature of a heat-conductive line with a hidden top shell.

FIG. 35 is a plan view of a sensor for detecting a temperature of a heat-conductive line with a hidden top shell and a hidden bottom shell.

DETAILED DESCRIPTION

The following detailed description illustrates embodiments of the present disclosure. These embodiments are described in sufficient detail to enable a person of ordinary skill in the art to practice these embodiments without undue experimentation. It should be understood, however, that the embodiments and examples described herein are given by way of illustration only, and not by way of limitation. Various substitutions, modifications, additions, and rearrangements may be made that remain potential applications of the disclosed techniques. Therefore, the description that follows is not to be taken as limiting on the scope of the appended claims. In particular, an element associated with a particular embodiment should not be limited to association with that particular embodiment but should be assumed to be capable of association with any embodiment discussed herein.

FIG. 1A is a block diagram for a system for sensing air conditioner parameters. The system for sensing air conditioner parameters 100 includes a processor 102, which may include a short-term memory, a long-term memory, input/output, and other typical elements of a processor. The system 100 includes sensors 104, 106 that sense parameters of an air conditioning system 108. The air conditioning system 108 is typically a residential air conditioning system. The processor 102, which may include circuitry to condition the signals from the sensors 104, 106, processes the signals and determines the health of the air conditioning system 108 based on that processing.

The processor 102 may send the raw data, the processed signals, or its analysis of those signals to a cloud-based system 112. The cloud-based system 112, which is a computer system that may have a processor, input/output, short-term memory, long-term memory, and other typical elements of a computer system, may perform an analysis of those signals or analyses in concert with signals and/or analyses from other air conditioning systems 114 to determine the health of the air conditioning system 108 and provide reports to an interested party or to interested parties. The reports may take several forms such as actionable data for an air conditioner technician that could be sent to a service provider 116, recommendations for service, including predictive failure analysis for preventing downtime, or recommended changes in usage patterns that could be sent to a system owner 118 or to a consumer (not shown), or reports of trends or recurring problems in air conditioner models that could be sent to a manufacturer 120. Generally, the cloud-based system 112 may provide air conditioning system 108 performance metrics and degradation profiles for consumers, technicians, power companies, manufactures, etc. The reports may be about a specific air conditioner (e.g., low on coolant, excess vibration, power out, etc.), a manufacture's model (e.g., the model tends to run longer than models from other manufacturers to achieve the same result, the model tends to vibrate more than other models from the same manufacturer, a set of air conditioner compressor/condensers manufactured during a specific time period tends to vibrate more than those manufactured in other time periods, etc.), or a manufacturer (the models manufactured by a particular manufacturer tend to consume more coolant as compared to models manufactured by other manufacturers). Manufacturers, installers, other interested parties may commission the cloud-based system to produce studies of particular interest to the interested party.

The processor 102 may provide data to the cloud-based system 112 in real time. The cloud-based system may allow real-time monitoring and diagnosis, as well as predictive capabilities which could be enhanced via machine learning using a large data set, provided, for example, by a large number of systems for sensing air conditioner parameters, such as the system for sensing air conditioner parameters 100 illustrated in FIG. 1, in diverse environments, and feedback from such systems in the field (for example, does a particular reading from one of the sensors 104, 106, lead to expected maintenance issues or should the expectations be adjusted?).

The processor 102 may also interface with a misting system 122, such as the systems described in U.S. Pat. Nos. 9,198,980 and 9,134,039, in U.S. patent application Ser. No. 14/851,146 now issued as U.S. Pat. No. 10,251,316, and in the systems manufactured by Mistbox, Inc., that may have its own set of sensors 124, different from sensors 104 and 106, and a mister.

For example, the processor 102 may determine, based on parameters of the air conditioning system 108 that it detects through the sensors 104, 106, that the misting system 122 should or should not be misting. Similarly, the misting system 122 may provide information, such as a thermostat setting or a sensed vibration in the air conditioner compressor, that the processor 102 may use as information to include or influence the signals or analysis that it prepares and/or sends to the cloud-based system 112.

The misting system 122 may be a misting-focused slave device that is a subsystem of the system for sensing air conditioner parameters 100 illustrated in FIG. 1. Further, the processor 102 may be incorporated in the packaging for the misting system 122, such as the misting system available from Mistbox, Inc., and the sensors 104, 106 may interface with the sensor ports on that system.

The sensors 104, 106, may be different from the sensors that are part of the mister and sensors 124 and may improve the precision of the diagnosis capability by introducing a second sensing system on the interior components of the air conditioning system 108.

FIG. 1B is a simplified block diagram of an air conditioning system. An example air conditioning system 108 includes a compressor/condenser 150 and an evaporator 152. Typically, in a residential air conditioning system, the compressor/condenser 150 is outside the residence and the evaporator 152 is inside the residence or in the attic. Other configurations are contemplated, such as “package units” in which the condenser and the evaporator are in the same enclosure. Coolant circulates between the compressor/condenser 150 and the evaporator 152 by way of coolant lines 154. Air circulates between the evaporator 152, ducting 156, registers 158, return 160, and return ducting 162. An overflow drain pan 164 receives excess moisture from the evaporator and is drained by an evaporator drain line 166. A fan 168 is mounted to the compressor/condenser 150 to facilitate heat exchange between a condenser coil, carrying refrigerant, in the compressor/condenser 150 and the environment.

On-board and auxiliary sensors, such as sensors 104, 106, may provide the capability to measure one or more of the following parameters outside the structure being air conditioned:

-   -   Condenser unit fan motor condition/strength     -   Condenser unit fan motor operation     -   Condenser unit compressor condition     -   Condenser unit compressor operation     -   Condenser unit startup capacitor condition     -   Condenser unit startup capacitor operation     -   Condenser unit contactor operation     -   Suction refrigerant line temperature     -   Liquid refrigerant line temperature     -   Suction refrigerant line pressure     -   Liquid refrigerant line pressure     -   Condenser unit coil condition     -   Total condenser unit power draw     -   Condenser unit fan motor power draw     -   Condenser unit fan compressor power draw     -   Condenser unit compressor run time     -   Condenser unit fan run time and/or one or more of the following         parameters inside the structure being air conditioned:     -   Air temperature on the inlet side of the evaporator,     -   Air temperature on the outlet side of the evaporator,     -   Presence of moisture in the overflow drain pan,     -   Moisture level/flow/presence in the evaporator drain line, or         air flow or pressure in ducting,     -   Evaporator blower motor condition     -   Evaporator blower motor operation     -   Evaporator blower motor power draw     -   Evaporator relay operation     -   Evaporator coil temperature     -   Evaporator blower motor run time     -   Air vent filter condition     -   Air vent leakage     -   Air vent pressure     -   Air vent air flow     -   Condensation pan moisture presence     -   Condensation drain line moisture flow and presence     -   Vent temperature—pre evaporator coil     -   Vent temperature—post evaporator coil

FIG. 2 is a rendering of components for sensing air conditioner parameters. The components include a sensor concentrator 201, a generator 202, a suction line temperature sensor 204, a liquid line temperature sensor 206, a cable 208 for coupling the generator 202 to the sensor concentrator 201, and a cable 210 for coupling the suction line temperature sensor 204 and the liquid line temperature sensor 206 to the sensor concentrator 201, and two protective plugs 212 that can be removed from the back of the sensor concentrator 201 to expose additional electrical sockets. The suction line temperature sensor 204 and the liquid line temperature sensor 206 may be interchangeable.

The generator 202 generates power for the system 100 without the need to be connected to the power grid. For example, the generator 202 illustrated in FIG. 2 is intended to be placed in the stream of the air blown by the compressor/condenser 150 and includes a fan-power generator that generates power when the compressor/condenser 150 is active. Such a generator can also provide information about the fan strength by measuring the power generated by the generator 202. That information can be used to help diagnose the health of the system 100. The generator may also be a solar generator or another type of generator that generates power without being connected to the power grid. Such a generator may be included in other components illustrated in FIG. 2, such as the sensor concentrator 201, instead of or in addition to the generator 202. For example, a solar cell may be mounted on the sensor concentrator 201 and may augment the power generated by the generator 202 when the sensor concentrator 201 is exposed to light. Such a system may provide power even when the compressor/condenser 150 is not active. In addition, a re-chargeable battery system may be provided that stores power when the compressor/condenser 150 is not active and/or when the sensor concentrator 201 is not exposed to light. Other forms of power generation are also contemplated, including a wind turbine that generates power using atmospheric air movement, a generator that operates off changes in temperature, and/or a generator that operates off changes in atmospheric pressure, and/or a generator that operates off vibrations or movements of the compressor/condenser 150.

The processor 102 may be included in the sensor concentrator 201 or in the generator 202 or in some other convenient location.

Power may be transmitted from the generator 202 to the sensor concentrator 201 and then distributed to the processor 102, the sensors (e.g., sensors 204, 206), and other equipment in the system 100 as needed.

The sensor concentrator 201 receives signals from the sensors (e.g. sensors 204, 206) and formats the data into a form (e.g., a serial stream of data) that it can be transmitted to the processor 102 (which may be in the generator 202, the sensor concentrator 201, or in another convenient location).

The components illustrated in FIG. 2 are readily installed by an untrained person. For example, the generator 202 may be secured to the top of the compressor/condenser 150, the sensor concentrator 201 may be secured to the side of the compressor/condenser 150, the sensors 204, 206 may be coupled to the suction line and the liquid line, and cable 208 may be run from the generator 202 to the sensor concentrator 201 and the cable 210 can be run from the sensors 204, 206 to the sensor concentrator 201, all without requiring technical skill.

FIG. 3 is a rendering of a sensor for detecting a temperature of a heat-conductive line. The suction line temperature sensor 204 or the liquid line temperature sensor 206 may be coupled to a heat-conductive line with a conductive paste 302 to increase thermal conductivity between the line and the sensor. An Allen wrench 304 may be used to tighten the sensor 204, 206 onto the heat-conductive line. An abrasive ribbon 306 may be used to clean the line before applying the conductive paste 302 and installing the sensor 204, 206.

FIG. 4 is a rendering of the connection of sensors to an air conditioner compressor. The suction line temperature sensor 204 and the liquid line temperature sensor 206 are shown coupled to their respective lines and to a cable 210.

FIG. 5 is a rendering of components for sensing air conditioner parameters. The generator 202, the suction line temperature sensor 204, the liquid line temperature sensor 206, the cable 208, and the cable 210 are shown. The components can have different colors, as can be seen by comparing FIG. 2 to FIG. 5.

FIG. 6 is a rendering of a generator positioned over a compressor/condenser fan. The generator 202 may be coupled to the compressor/condenser 150 over the compressor/condenser fan 168 and may be coupled to the processor 102 by cable 208.

FIG. 7 is a rendering of a generator positioned over a compressor/condenser fan. The generator 202 may be coupled to the compressor/condenser 150 over the compressor/condenser fan 168 and, if the processor 102 is not located in the generator 202, it may be coupled to the processor 102 by cable 208. The suction line temperature sensor 204 and the liquid line temperature sensor 206 may be coupled to the processor 102 by one or more cables 201, which may be daisy-chained together as shown in FIG. 7 depending on the configuration or quantity of sensors being installed.

FIG. 8 is a rendering of a generator positioned over a compressor/condenser fan. The generator 202 may be coupled to the compressor/condenser 150 over the compressor/condenser fan 168 and, if the processor 102 is not located in the generator 202, it may be coupled to the processor 102 by cable 208.

FIG. 9 is a rendering of a device for sensing air conditioner parameters coupled to the air conditioner compressor. A power draw sensor 902 may be coupled around a wire 904 leading to a contactor 906 for the compressor/condenser 150. A cable 208 may couple the power draw sensor 902 to the processor 102. Arranged as shown, the power draw sensor 902 may detect when the contactor 906 engages and/or disengages, which may indicate a power state change for the compressor/condenser 150.

FIG. 10 is a rendering of components, some do-it-yourself installations and some requiring a tech installation, for sensing air conditioner compressor/condenser parameters. The generator 202, the suction line temperature sensor 204 and the liquid line temperature sensor 206 may be do-it-yourself installations, meaning that no technical training is required to perform an installation. The power draw sensor 902 may require technical training to be installed. A cable 210 and an extension cable with a right-angle connection 1002 are shown.

FIG. 11 is a rendering of components for sensing air conditioner parameters. The generator 202, the suction line temperature sensor 204, the liquid line temperature sensor 206, and the cable 208 are shown.

FIG. 12 is a rendering of components for sensing air conditioner parameters. The generator 202, the suction line temperature sensor 204, the liquid line temperature sensor 206, the power draw sensor 902, and cables 210 are shown.

FIG. 13 is a rendering of components for sensing air conditioner parameters. The generator 202, the suction line temperature sensor 204, and the liquid line temperature sensor 206 are shown.

FIG. 14 is a rendering of components for sensing air conditioner parameters. The generator 202, the suction line temperature sensor 204, and the liquid line temperature sensor 206 are shown.

FIG. 15 is a rendering of components for sensing air conditioner parameters. The generator 202, the suction line temperature sensor 204, and the liquid line temperature sensor 206 are shown.

FIG. 16 is a rendering of a generator. The generator 202 is shown.

FIG. 17 is a rendering of a generator. The generator 202 is shown.

FIG. 18 is a rendering of a generator. The generator 202 is shown.

FIG. 19 is a rendering of sensors for detecting a temperature of a heat-conductive line. The suction line temperature sensor 204 and the liquid line temperature sensor 206 are shown.

FIG. 20 is a rendering of sensors for detecting a temperature of a heat-conductive line. The suction line temperature sensor 204, the liquid line temperature sensor 206, and the cable 210 are shown.

FIG. 21 is a rendering of a generator. The generator 202 is shown. The suction line temperature sensor 204, the liquid line temperature sensor 206, and the cable 210 are shown.

FIG. 22 is a rendering of sensors for detecting a temperature of a heat-conductive line. The suction line temperature sensor 204, the liquid line temperature sensor 206, and the cable 210 are shown.

FIG. 23 is a rendering of a cable. An extension cable with a right-angle connection 1002 is shown.

FIG. 24 is a rendering of a cable. The cable 210 is shown.

FIG. 25 is a rendering of a power draw sensor. The power draw sensor 902 is shown.

FIG. 26 is a rendering of the connection of sensors to an air conditioner compressor. A generator 202, a suction line temperature sensor 204, a liquid line temperature sensor 206, a power draw sensor 902, and cables 208, 210 are shown.

FIG. 27 is a rendering of the connection of sensors to an air conditioner compressor. The generator 202, the suction line temperature sensor 204, the liquid line temperature sensor 206, the power draw sensor 902, and cables 208, 210 are shown.

FIG. 28 is a rendering of an air conditioner compressor/condenser with a generator installed. The generator 202, the suction line temperature sensor 204, the liquid line temperature sensor 206, and cables 208, 210 are shown.

FIG. 29 is a rendering of an air conditioner compressor/condenser with a generator installed. The generator 202, the suction line temperature sensor 204, the liquid line temperature sensor 206, the power draw sensor 902, and cables 208, 210 are shown.

FIG. 30 is a rendering of an air conditioner compressor/condenser with a generator installed. The generator 202 and the cable 208 are shown.

FIG. 31 is a perspective view of a sensor for detecting a temperature of a heat-conductive line. The suction line temperature sensor 204 and the liquid line temperature sensor 206 include an upper shell 3102 and a lower shell 3104 that pivot with respect to each other and, when positioned as shown in FIG. 31, include a line passage 3106 through which the line being monitored passes. The upper shell 3102 and lower shell 3104 open like jaws to admit the line being monitored into the line passage 3106. The suction line temperature sensor 204 and the liquid line temperature sensor 206 include a cable 3108 by which power is delivered to the suction line temperature sensor 204 and the liquid line temperature sensor 206 and by which signals are transmitted from the suction line temperature sensor 204 and the liquid line temperature sensor 206 to the processor 102. The suction line temperature sensor 204 and the liquid line temperature sensor 206 may include a fastening mechanism, i.e., a cap screw 3110 and dowel nut 3112, which may be adjusted by the Allen wrench 304 (see FIG. 3). Other adjustments mechanisms may be used, such as a thumb screw or some such tool-less fastener.

FIG. 32 is a plan view of a sensor for detecting a temperature of a heat-conductive line. FIG. 31 provides another view of the same components as in FIG. 31.

FIG. 33 is a perspective view of a sensor for detecting a temperature of a heat-conductive line with a hidden top shell. The suction line temperature sensor 204 and the liquid line temperature sensor 206 are shown in FIG. 33 from the same perspective as FIG. 31 with the difference between the two figures being that in FIG. 33 the upper shell 3102 is hidden. An upper jaw 3302 and a lower jaw 3304 form the line passage 3106. A thermocouple temperature sensor 3306 engages with the upper jaw 3302. Wires 3308 carry a signal representing the temperature of the line in the line passage 3106 from the thermocouple temperature sensor 3306 to a circuit 3310. The circuit 3310 amplifies and conditions the signal from the thermocouple temperature sensor 3306 and delivers it to processor 102 via the cable 3108. A hinge 3312 allows the upper shell 3102 to rotate with respect to the lower shell 3104.

FIG. 34 is a plan view of a sensor for detecting a temperature of a heat-conductive line with a hidden top shell. The suction line temperature sensor 204 and the liquid line temperature sensor 206 include a conductive plate 3402 which contacts the line being monitored. Clips 3314 secure the conductive plate 3402 to the upper shell 3102. Heat conduction is improved by cleaning the line to be monitored with the abrasive ribbon 306 and coating the conductive plate 3402 or the cleaned area of the line to be monitored with the conductive paste 302 illustrated in FIG. 3.

FIG. 35 is a plan view of a sensor for detecting a temperature of a heat-conductive line with a hidden top shell and a hidden bottom shell. The upper shell 3102 includes features 3502 that engage with the hinge 3312.

The operations of the flow diagrams are described with references to the systems/apparatus shown in the block diagrams. However, it should be understood that the operations of the flow diagrams could be performed by embodiments of systems and apparatus other than those discussed with reference to the block diagrams, and embodiments discussed with reference to the systems/apparatus could perform operations different than those discussed with reference to the flow diagrams.

The word “coupled” herein means a direct connection or an indirect connection.

The text above describes one or more specific embodiments of a broader invention. The invention also is carried out in a variety of alternate embodiments and thus is not limited to those described here. The foregoing description of an embodiment of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. 

What is claimed is:
 1. A system comprising: a cloud-based system; a plurality of systems for sensing air conditioner parameters coupled to the cloud-based system; wherein each of the plurality of systems for sensing air conditioner parameters senses parameters about a respective air conditioning system and forwards the sensed parameters to the cloud-based system; wherein the cloud-based system receives the parameters from the plurality of systems for sensing air conditioner parameters, determines a maintenance condition, and forwards the maintenance condition to an interested party.
 2. The system of claim 1 wherein the interested party is one or more of a manufacturer, a service provider, a system owner, and a consumer.
 3. The system of claim 1 wherein one of the plurality of systems for sensing air conditioner parameters includes a misting system.
 4. The system of claim 1 wherein the maintenance condition concerns exactly one of the air conditioning systems.
 5. The system of claim 1 wherein the maintenance condition concerns an air conditioner model.
 6. The system of claim 1 wherein the maintenance condition concerns a manufacturer.
 7. A method comprising: a cloud-based system receiving parameters about a plurality of air conditioning systems from respective systems for sensing air conditioner parameters; the cloud-based system determining a maintenance condition; the cloud-based system forwarding the maintenance condition to an interested party.
 8. The method of claim 7 wherein one of the systems for sensing air conditioner parameters receives information from a misting system.
 9. An apparatus for measuring a temperature of a line, comprising: an upper shell; a lower shell coupled to the upper shell by a hinge; a line passage formed when the upper shell is closed to the lower shell; a conductive plate adjacent to the line passage; and a temperature sensor thermally coupled to the conductive plate.
 10. The apparatus of claim 9 further comprising: a circuit coupled to the temperature sensor to amplify and condition a signal from the temperature sensor.
 11. The apparatus of claim 9 further comprising: a fastening mechanism for opening and closing the upper shell and lower shell around the hinge.
 12. The apparatus of claim 11 wherein the fastening mechanism comprises: a screw that engages the lower shell; and a dowel nut that engages the upper shell and the screw.
 13. A system for monitoring the health of a residential air conditioning system that includes a compressor/condenser unit, comprising: a sensor that can be mounted on the compressor/condenser unit and that senses a parameter of the residential air conditioning system that can be used to monitor the health of the residential air conditioning system; a power source that can be mounted on the compressor/condenser unit and that generates power using environmental conditions created by the compressor/condenser unit without accepting power from the power grid; a processor that receives a signal representing the parameter from the sensor and uses that signal to monitor the health of the residential air conditioning system.
 14. The system of claim 13 wherein the power source is a sensor.
 15. The system of claim 13 wherein the processor is incorporated in a housing with the power source.
 16. The system of claim 13 wherein the processor is incorporated in a housing with the sensor.
 17. The system of claim 13 wherein the power source comprises a fan generator that can be mounted in a flow of air caused by a fan in the compressor/condenser unit.
 18. The system of claim 17 wherein the fan generator is also a sensor that detects operation of the compressor/condenser unit. 